iRiver H10 20g detection problem

[Mortal Light]

I just purchased an iRiver H10 20g from ebay and I cannot add music to it because it is not detected by the computer. It was detected and even loaded a few songs the first two times it was connected to the computer, but it is no longer detected. I used wmp10 to add the songs and upgraded to wmp11 after the detection problem started. Is there anything that can be done to solve this problem?